Mine was almost 20 years ago but knowing now and what's available now compared to then I have 2 words for you
Tena pants!
Get the granny pants ones rather than bikini style very high waisted but actually very soft with no hard seams or waistband or leg openings which will help with catheter and they should cope with a lot of blood loss too plus if necessary.
Nightdress rather than pj's - again you don't want a hard waistband but you will want covered up and if you're planning on bf then get one that opens for such.
With a section it takes longer for your milk to come in so be aware of that.
Big warm cardi or wrap, it's hot on the wards but can be chilly in the corridors (which you may spend a fair bit of time walking down depending on where baby is in relation to you) and if you want/need to go down to the shop/s they're often near the main entrance and can be freezing area! Or even if you just want some fresh air!
Eye mask! Maybe consider ear plugs too. Hospitals are MURDER to get a rest in not least due to lights going on and off constantly, to allow hcps to see properly to meet other patients needs.
A comfy crop top type bra and breast pads - whether you're bf or not you'll still probably have tender breasts that need support when you're moving about and pads for any leaks
Stuff to make you feel "fresh" wipes, deodorant, dry shampoo, even that spray water you see advertised for holidays can all help, i had dd in winter and I still went through a shit load of face wipes to cool me down!
Good luck with it all